Influence of age and fitness level on immune responses of T and NK cells in healthy physically active subjects after strenuous aerobic exercise: a cross-sectional study.

Aim: The aim of this study is to analyze whether immune responses after strenuous exercise are influenced by chronological age and fitness level in physically active healthy men. Methods: Cross-sectional study with a sample of 32 physically active men. Participants were divided into two groups based on chronological age (younger: age 21.8 ± 1.8 vs. older: age 34.6 ± 8.3) and subsequently regrouped and divided based on fitness level (More conditioned: excellent and superior VO2max vs. Less conditioned: VO2max: weak, regular and good). Fitness was classified according to VO2max levels obtained by a treadmill test using a gas analyzer. Before and immediately after the ergospirometry test, blood samples were collected for evaluation of immunological markers: leukocytes, neutrophils, lymphocytes and subpopulations. Results: Chronological age had a moderate effect on CD3+CD4+ lymphocyte count (effect size: 0.204) and CD4/CD8 ratio (effect size: 0.278), favoring older subjects. The level of physical fitness had no significant effect on the analyzed immunological markers. Conclusions: Immune responses observed immediately after strenuous exercise may be more dependent on chronological age than on fitness level in healthy, physically active men.

Relative age effects on speed trials in Brazilian athletics.

BACKGROUND: Relative age effect (RAE) is a concept related to the possible advantage that older athletes would have over younger ones within the same category. Although many studies have approached this subject in individual sports, there are few clippings by events within the sport. More detailed analyses are necessary for a better understanding of how RAE behaves in sports, especially in athletics, the subject of this study. The objective of this study was to analyze the RAE on speed in track and field events as a whole, separating the flat races from the hurdles races. METHODS: The Brazilian Ranking of Brazilian Athletics Confederation was used for data analysis, and the sample was composed of the 50 best-placed marks in the ranking of speed events in athletics in the categories Under(U)-16 and U-18 (female and male). Statistical analysis was calculated by chi-square, and the effect size was checked by Cramer's V. Likelihood-ratio test (L-Ratio) assessed the probability of the RAE occurring in the total sample and by age groups. RESULTS: In the total sample the results pointed to the emergence of RAE in males in both categories (U-16: p < 0.001; V: 0.13; L-Ratio: 3.64, U-18: p < 0.001; V: 0.13; L-Ratio: 3.80), whereas in females no such effect was found in any category (U-16: p = 0.6; V: 0.09; L-Ratio: 0.09, U-18: p = 0.6; V: 0.07; L-Ratio: 0.12). When the results were separated by type of event, there was only a RAE in the shallow event in the U-18 female category (p = 0.3; V: 0.11; L-Ratio: 8.72). CONCLUSION: The results allow us to conclude that there is a RAE in the speed trials of Brazilian athletics in the U16 and U18 categories for men, while this effect appears only in the shallow trials of the U18 category for women, indicating that the RAE has incidence when there is more participation and competition in the sport.

Could cardiac autonomic modulation be an objective method to identify hypobaric hypoxia symptoms at 25.000ft among Brazilian military airmen?

Hypobaric hypoxia during a flight can cause accidents, resulting in deaths. Heart rate variability may be more sensitive than self-reported hypoxia symptoms to the effects of HH. The level of physical fitness can contribute to efficient cardiac autonomic modulation. However, no studies have examined the association between fitness, heart rate variability, and the time of onset of hypobaric hypoxia symptoms. To analyze the influence of hypobaric hypoxia on cardiac autonomic function at the time of onset of the first symptoms and its association with physical fitness. Male airmen trained and belonging to the staff of the Brazilian Air Force (n = 23; 30 ± 6.7 years) participated in a flight simulation in a 25.000 ft hypobaric chamber. Heart rate variability was recorded with a Polar® cardiac monitor. Data were analyzed in the time-domain method using Kubios software. We evaluated pulse oximetry with the Mindray PM-60 oximeter. Physical fitness assessment test results were collected from the archive. At moments rest vs. hypoxia revealed a decrease in heart rate variability indices iRR and RMSSD (p < 0.001). The individual analysis of hypoxia-rest variation showed that 100% of the airmen had a negative delta for both iRR and RMSSD indices. The time of onset of hypoxia symptoms was not associated with body composition, physical fitness, oxygen saturation, and HRV indices. Also, we suggest that cardiac autonomic modulation seems to be more sensitive to the effects of hypobaric hypoxia at 25.000 ft than the self-reported subjective perception of symptoms. Further devices that alert to a hypoxic condition during a flight should consider heart rate variability allowing more time and security to reestablish control of the flight.

Reliability of biological maturation analyses performed by equations predicting skeletal age and peak height velocity with hand and wrist X-ray results.

BACKGROUND: Hand-wrist radiography is the gold standard for the assessment of skeletal age (SA) and the assignment of biological maturation (BM) status. However, its practical use in the field is questioned, prompting the development of anthropometric equations to estimate BM. However, there is no consensus on the reliability of these equations in relation to hand-wrist X-rays. OBJECTIVE: To test the reliability of the BM estimated from predictive equations with the results of hand-wrist X-rays. METHODS: One-hundred forty-four young athletes (38%-males, 62%-females; 12.3 ± 1.4 years) were recruited. SA was assessed by analyzing X-rays of the hand-wrist using the Greulich-Pyle protocol. SA was predicted using the anthropometric equations of Cabral and Macêdo. By subtracting chronological age from SA, a measure of BM or biological age (BA) was computed. In addition, a BA of years from peak height velocity (PHV) was predicted using the anthropometric equations of Mirwald and Moore. RESULTS: Relative to X-ray, Cabral's equations showed high reliability in estimating BM in both sexes (p < .0001) while Macêdo's equations showed substantial reliability or males (p < .0001) only. Mirwald and Moore's equations showed weak reliability (p < .05 and p = .043, respectively). CONCLUSION: The prediction of SA using anthropometric equations was found to be reliable in categorizing individuals as late, synchronized, and/or early maturers in both sexes. However, the predictive equations of years from PHV only reliably categorized late and synchronized maturation stages in males and the synchronized maturers in females.

Performance of postural balance in children and adolescents living with and without HIV.

RESEARCH QUESTION: The present study aimed to compare the postural control of children and adolescents with and without Human Immunodeficiency Virus (HIV). METHODS: A total of 32 children and adolescents (18 with HIV and 14 without) of both sexes, aged 6-18 years, were included in the present study. Participants in the HIV + group were infected through vertical transmission and received antiretroviral therapy. Participants maintained an erect, bipedal posture in the following conditions: with vision, without vision, and on a foam base. RESULTS: Concerning the evaluation of time variables, higher values ​​were observed in the HIV + group for mean anterior-posterior (AP) velocity, mean medial-lateral (ML) velocity, AP perimeter (p = 0.001), and ML perimeter (p = 0.001). Concerning the evaluation of conditions, a difference was observed in the mean AP mean sway amplitude (MSA) (p = 0.039), as the AP MSA was lower with vision than without vision or with foam. Concerning the evaluation of spectral domain variables, higher values ​​were observed in the HIV+ group for the predominant ML frequency (p = 0.04) and mean AP (p = 0.001) and ML frequencies (p = 0.001). Regarding the evaluation of conditions, a difference was found only in the predominant AP frequency (p = 0.001). Higher values ​​were found in the closed eye condition than in with foam (Δ = +103 %). CONCLUSION: The results of the present study indicated that children and adolescents living with HIV have poorer postural control performance than those without HIV.

Effect of Training and Detraining in the Components of Physical Fitness in People Living With HIV/AIDS.

The aim of the study was to evaluate the effect of training and detraining on the physical fitness components of people living with HIV/AIDS (PLHA). The study was characterized as experimental with a sample composed of 21 people divided into two groups: 11 volunteers (PLHA, 46.9 ± 8.0 years, 63.8 ± 12.7 kg, 161.7 ± 8.7 cm, 7 men, and 4 women), using antiretroviral therapy (ART) and 10 people without HIV/AIDS in the control group (CG, 43.8 ± 13.8 years, 75.2 ± 11.2 kg, 163.3 ± 7.8 cm, 3 men, and 7 women), with the same average age and level of physical activity. The intervention, applied to both groups, consisted of combined training for 15 weeks, followed by detraining for 5 weeks. Before and after the training and detraining period the following parameters were evaluated: body composition by dual energy radiological absorptiometry (DXA), cardiorespiratory fitness by ergospirometer, and strength of upper and lower limbs by isometric dynamometer. The results show the effect of the intervention moments on the strength and oxygen consumption variables (time factor), considering the two study groups. Regarding the analysis of the interaction (group vs. time), there was a significant effect on the isometric extension strength of the left (p = 0.019) and right (p = 0.030) knees, with training (left: 10.4%; right: 12.4%) and detraining (left: -10.8%; right: -12.1%) effect in PLHA, when compared with the control group (left: 8.1 and 3.9%, respectively; right: 11.5 and -0.2%, respectively). In addition, there was a significant interaction on ventilatory threshold 1 (p = 0.002), indicating a significantly greater increase with training (27.3%) and decrease with detraining (-22.7%) in the PLHA group compared with the Control group (19.9 and -6.7%, respectively). In conclusion, combined training and the subsequent period of detraining caused similar responses in body composition, isometric strength, and cardiorespiratory fitness of PLHA and CG, except for the extensor strength of the lower limbs and ventilatory threshold 1, which presented positive effects on training and negative effects on detraining for PLHA. Clinical Trial Registration:www.ClinicalTrials.gov, identifier NCT03075332.

Do heart rate variability is relationed to endurance performance in female futsal players? / A variabilidade da frequência cardíaca está relacionada ao desempenho de resistência em jogadoras de futsal?

abstract The study aimed to verify the correlation between resting heart rate variability (HRVrest) and endurance performance in female futsal players, as well as to evaluate the reliability of this parasympathetic autonomic marker. A total of 16 female futsal players (age: 22 ± 3 years; VO2max: 42.3 ± 2.0 ml.kg-1.min-1) were evaluated during the first week of preseason training. Vagal modulation was evaluated from the HRVrest (i.e., log-transformed root mean square of successive R-R interval differences - Ln-RMSSD) for two consecutive days, while endurance performance was evaluated by the Yo-Yo Intermittent Recovery Test, Level 1 (Yo-Yo IR1). Pearson correlation was used to analyze the relationship between the variables. Strong correlation between the HRVrest index and endurance performance (r = 0.643; p = 0.007). Reliability was tested through the intraclass correlation coefficient, coefficient of variation (CV), and Bland-Altman analysis of the agreement. Furthermore, acceptable repeatability of HRVrest, but with great inter-subject variability (ICC = 0.670, 95%CI = 0.056-0.885, CV = 15.8%). The current study demonstrated a strong correlation between Ln-RMSSD and endurance performance, and despite the acceptable values of intrasubject reliability, HRVrest presented high inter-individual variability in female futsal players.

resumo O objetivo do estudo foi verificar a correlação entre a variabilidade da frequência cardíaca de repouso (VFCRepouso) e o desempenho de resistência em jogadoras de futsal, bem como avaliar a confiabilidade do marcador parassimpático. No total, 16 jogadoras de futsal (idade: 22 ± 3 anos; VO2max: 42.3 ± 2.0 ml.kg-1.min-1) foram avaliadas durante a primeira semana de treinamento da pré-temporada. A modulação vagal foi avaliada a partir da VFC de repouso (isto é, raiz quadrada da média das diferenças sucessivas ao quadrado dos intervalos R-R adjacentes - Ln-RMSSD) por dois dias consecutivos, enquanto o desempenho da resistência foi avaliado pelo Yo-Yo Intermittent Recovery Test, Level 1 (Yo-Yo IR1). A correlação de Pearson foi utilizada para analisar a relação entre as variáveis. A confiabilidade foi testada através do coeficiente de correlação intraclasse, coeficiente de variação e análise de concordância de Bland-Altman. Observou-se uma forte correlação entre o índice de VFCrepouso e o desempenho de endurance (r = 0,643; p = 0,007). Por outro lado, repetibilidade aceitável dos índices de repouso vagal, mas com grande variabilidade interindividual (ICC = 0,670, IC = 0,056-0,885, CV = 15,8%). O presente estudo apresentou forte correlação entre Ln-RMSSD e desempenho de endurance, e mesmo com valores aceitáveis de confiabilidade intrasujeito, a VFC em repouso apresentou alta variabilidade interindividual em jogadoras de futsal.

Effects of Pre-exhaustion Versus Traditional Resistance Training on Training Volume, Maximal Strength, and Quadriceps Hypertrophy.

BACKGROUND: The pre-exhaustion (PreEx) method is used as a resistance training (RT) method to increase muscle mass, yet the chronic effects of this method are poorly understood. OBJECTIVE: Although readily prescribed as a RT method for promotion of muscle hypertrophy, few researches give light to gains made after chronic PreEx RT. Therefore, we compared the effects of traditional versus PreEx RT programs on muscle strength, body composition, and muscular hypertrophy in adult males. METHODS: Untrained subjects (age: 31.37 ± 6.83 years; height: 175.29 ± 5.52 cm; body mass: 82.04 ± 13.61 kg; 1RM leg press: 339.86 ± 61.17 kg; 1RM leg extension: 121.71 ± 11.93 kg) were submitted to 9 weeks of RT with weekly sessions. Traditional (TRT) group (n = 12) performed three sets at 45° of leg press exercise at 75% of 1RM, PreEx group (n = 12) completed a set to failure on a leg extension machine prior to the leg press, and the control (CON) group (n = 7) did not train. Maximum strength, muscle thickness, and body composition were analyzed. RESULTS: PreEx group increased in maximal strength on leg press (16 ± 8%) and leg extension (17 ± 11%), while the TRT group improved by 15 ± 9 and 11 ± 4%, respectively. The thickness of the quadriceps muscles increased for both intervention groups. Specifically, the post-training thickness of the vastus lateralis was significantly higher for PreEx (55%) compared to the CON group. The TRT group presented a greater loss of total and thigh fat mass when compared with the PreEx method. These results were found in the presence of a lower training load for the PreEx group. CONCLUSION: The PreEx training can decrease the total training volume while maintaining results in strength and hypertrophy when comparing to TRT. However, TRT may be optimal if the goal is to decrease fat mass.

Influence of curcumin supplementation on metabolic and lipid parameters of people living with HIV/AIDS: a randomized controlled trial.

BACKGROUND: Scientific studies have shown that the potential therapeutic efficacy of curcumin in several diseases is due to its potent antioxidant and anti-inflammatory properties. Consequently, curcumin supplementation seems to be a valuable alternative for HIV-infected individuals. The aim of this study is to evaluate the influence of curcumin supplementation on substrate oxidation at rest, body composition, and the lipid profile of physically active people living with HIV/AIDS under antiretroviral therapy. METHODS: This double-blind, crossover, randomized clinical trial was comprised of 20 subjects divided into experimental (EG) and control (CG) groups, receiving 1000 mg curcumin/day and placebo, respectively, during a 30-day period. Substrate oxidation at rest was assessed by indirect calorimetry, body composition was measured by dual-energy x-ray absorptiometry, and the lipid profile was evaluated by blood tests. Data analysis was performed by independent samples and paired t-tests to compare the differences between groups and times. A p-value < 0.05 was accepted as significant. RESULTS: There were no differences between groups regarding substrate oxidation at rest or body composition. However, serum triglyceride levels were increased after curcumin supplementation (182 vs. 219 mg/dL; p = 0.004). CONCLUSION: Curcumin supplementation promoted the elevation of serum triglyceride levels in HIV-infected subjects. Further studies with a larger sample cohort, different curcumin doses, and longer intervention times are needed to validate current observations. In addition, the influence of physical activity, dietary intake, and genetic polymorphisms must be considered in future studies to better understand the impact of curcumin supplementation on the lipid profile of people living with HIV/AIDS under antiretroviral therapy.

Impact of curcumin on energy metabolism in HIV infection: A case study.

Prolonged use of antiretroviral therapy (ART) has been associated with dyslipidemia and impaired energy substrate oxidation (SOxi). Curcumin is a natural bioactive compound, which interacts with molecular targets and holds important metabolic properties. The aim of this study was to evaluate the effect of curcumin supplementation on energetic metabolism of an adult female with HIV/AIDS and under ART. The intervention was performed with 500 mg/day of curcumin for 27 days. Glycemic and lipid profile and SOxi at rest were evaluated before and after intervention. After intervention, improvement of lipid profile and insulin sensibility was observed. Moreover, there was a positive modulation of SOxi at rest. Oral curcumin supplementation can positively modulate the energy metabolism of people living with HIV/AIDS using the ART. However, clinical studies are required in order to confirm our findings in a representative sample.

CONHECIMENTO NUTRICIONAL E ESTADO ANTROPOMÉTRICO DE ATLETAS UNIVERSITÁRIOS / NUTRITIONAL KNOWLEDGE AND ANTHROPOMETRIC STATUS OF UNIVERSITY ATHLETES / CONOCIMIENTO NUTRICIONAL Y ESTADO ANTROPOMÉTRICO DE ATLETAS UNIVERSITARIOS

Introdução O estudo do consumo alimentar fornece informações específicas sobre a ingestão de energia e nutrientes, podendo estar associado com o conhecimento sobre nutrição e alimentação. Nesse contexto, a entrada dos estudantes na universidade envolve uma tendência de transição nutricional e mudanças negativas no nível de atividade física, resultando em alterações importantes na sua composição corporal. Objetivo Analisar a relação entre perfil antropométrico e o conhecimento nutricional de atletas universitários de futebol. Métodos Participaram da pesquisa 37 universitários, jogadores de futebol, do sexo masculino, entre 18 e 28 anos, estudantes das áreas de Saúde e Biológica (SB), Tecnológica e Exatas (TE) e Humanas e Sociais (HS). Foram aferidas a massa corporal, estatura e dobras cutâneas (tricipital, subescapular, supra-ilíaca, abdominal e coxa medial). A fim de mensurar o conhecimento nutricional dos atletas, foi aplicado um questionário de conhecimento nutricional (QCN), traduzido, adaptado e validado para o Brasil. Para análise estatística foi utilizada correlação de Pearson e ANOVA one-way com post-hoc de Games-Howell. Resultados Foi observada diferença na massa corporal, estatura e massa livre de gordura (MLG) entre os atletas. Na comparação entre as áreas, verificou-se que não houve diferença significativa entre os estudantes da área SB em relação aos demais. Também foi observado que não houve diferenças significativas para a parte I, parte II ou total de acertos. Ainda houve correlação positiva, forte e significativa da área HS com a MLG. Observando-se as demais variáveis na área TE, foi encontrada correlação negativa e moderada. No restante das variáveis, as correlações entre a pontuação obtida no QCN e as variáveis de composição corporal foram fracas. Conclusão A amostra avaliada apresentou conhecimento nutricional moderado, verificando-se baixa associação deste com o perfil antropométrico. Os resultados também sugerem que o conhecimento nutricional, isoladamente, não é capaz de influenciar o comportamento alimentar.

Introduction The study of food consumption provides specific information on energy and nutrient intake, which may be associated to knowledge about food and nutrition. In this context, the entrance of students in university involves a trend of nutritional transition and negative changes in physical activity levels, resulting in significant changes in student's body composition. Objective To analyze the relationship between anthropometric profile and nutrition knowledge of university soccer players. Methods The participants were 37 male university soccer players, aged between 18 and 28 years old, students in the Health and Biological (HB), Technological and Exact (TE) and Human and Social (HS) areas. Body weight, height and skinfolds (triceps, subscapular, suprailiac, abdominal and medial thigh) were measured. In order to measure athletes' nutritional knowledge, we applied a nutritional knowledge questionnaire (NKQ), translated, adapted and validated for Brazil. For statistical analysis, Pearson's correlation and one-way ANOVA with Games-Howell post-hoc were used. Results Significant differences were observed in body mass, height and fat-free mass (FFM) among athletes. When comparing the areas, there was no significant difference between HB area students compared with others. It was also observed that there were no significant differences for part I, part II or total correct answers. There was also a positive, strong and significant correlation between HS and FFM. Observing other variables in TE area, a negative and moderate correlation was found. For the remaining variables, correlations between scores obtained in NKQ and body composition variables were weak. Conclusion The sample evaluated presented moderate nutritional knowledge, showing low association with the anthropometric profile. The results also suggest that nutritional knowledge alone is not able to influence eating behavior.

Introducción El estudio del consumo alimentario provee informaciones específicas sobre la ingestión de energía y nutrientes, pudiendo estar asociado con el conocimiento sobre nutrición y alimentación. En ese contexto, la entrada de los estudiantes a la universidad involucra una tendencia de transición nutricional y cambios negativos en el nivel de actividad física, resultando en alteraciones importantes en su composición corporal. Objetivo Analizar la relación entre perfil antropométrico y el conocimiento nutricional de atletas universitarios de fútbol. Métodos Participaron en la investigación 37 universitarios, jugadores de fútbol, del sexo masculino, entre 18 y 28 años, estudiantes de las áreas de Salud y Biológica (SB), Tecnológica y Exactas (TE) y Humanas y Sociales (HS). Fueron medidas la masa corporal, estatura y pliegues cutáneos (tricipital, subescapular, suprailíaco, abdominal y muslo medial). A fin de medir el conocimiento nutricional de los atletas, fue aplicado un cuestionario de conocimiento nutricional (QCN), traducido, adaptado y validado para Brasil. Para análisis estadístico fue usada la correlación de Pearson y ANOVA one-way con post-hoc de Games-Howell. Resultados Fue observada diferencia en la masa corporal, estatura y masa libre de grasa (MLG) entre los atletas. En la comparación entre las áreas, se verifico que no hubo diferencia significativa entre los estudiantes del área SB en relación a los demás. También se observó que no hubo diferencias significativas para la parte I, parte II o total de aciertos. Además, hubo correlación positiva, fuerte y significativa del área HS con la MLG. Observándose las demás variables en el área TE, fue encontrada correlación negativa y moderada. En el resto de las variables, las correlaciones entre la puntuación obtenida en el QCN y las variables de composición corporal fueron débiles. Conclusión La muestra evaluada presentó conocimiento nutricional moderado, verificándose baja asociación de éste con el perfil antropométrico. Los resultados también sugieren que el conocimiento nutricional, aisladamente, no es capaz de influenciar el comportamiento alimentario.

[Contribution of anthropometric characteristics to pubertal stage prediction in young male individuals]. / Contribuição das características antropométricas na predição dos estádios de maturação puberal de jovens do sexo masculino.

OBJECTIVE: To identify the contribution of anthropometric variables to predict the maturational stage in young males. METHODS: Cross-sectional study that enrolled 190 male subjects aged between eight and 18 years, randomly selected from public and private schools in Natal, Northeast Brazil. Thirty-two anthropometric variables were measured following the recommendations of the International Society for the Advancement of Kineanthropometry (ISAK). The assessment of sexual maturation was based on the observation of two experienced experts, who identified the pubertal development according to Tanner guidelines (1962). RESULTS: The anthropometric variables showed a significant increase of their values during the advancement of pubertal development (p<0.05). The following variables showed the best value for prediction of maturational groups: sitting height, femoral biepicondylar diameter, forearm girth, triceps skinfold, tibiale laterale and acromiale-radiale bone lenghts. These variables were able to estimate the pubertal stages in 76.3% of the sujects. CONCLUSION: The anthropometric characteristics showed significant differences between the moments of maturational stages, being found, representatively, seven variables that best predict the stages of sexual maturation.

Contribuição das características antropométricas na predição dos estádios de maturação puberal de jovens do sexo masculino / Contribution of anthropometric characteristics to pubertal stage prediction in young male individuals

Objetivo: Identificar a contribuição de variáveis antropométricas para a predição do estádio maturacional em jovens do sexo masculino. Métodos: Estudo transversal, sendo investigados 190 sujeitos do sexo masculino, com idades entre 8 e 18 anos, selecionados aleatoriamente em escolas públicas e privadas de Natal. Foram selecionadas 32 variáveis antropométricas, todas avaliadas de acordo com as recomendações da International Society for the Advancement of Kineanthropometry (ISAK). A avaliação da maturação sexual se baseou na observação de dois especialistas experientes, que identificaram o desenvolvimento da genitália, segundo as recomendações propostas por Tanner (1962). Resultados: As variáveis antropométricas apresentaram um aumento significativo no decorrer do avanço do desenvolvimento puberal (p<0,05). As variáveis de altura troncocefálica, diâmetro biepicôndilo femural, perímetro de antebraço, dobra cutânea de tríceps, alturas ósseas tibial e acrômio-radial apresentaram a melhor relação para predição dos grupos maturacionais, sendo responsáveis por estimar os estádios puberais com índice de 76,3% de chance de acerto. Conclusão: As características antropométricas apresentaram diferenças significativas entre os momentos dos estádios maturacionais, sendo encontradas, de forma representativa, sete variáveis que melhor predizem os estádios de maturação sexual...

Objective: To identify the contribution of anthropometric variables to predict the maturational stage in young males. Methods: Cross-sectional study that enrolled 190 male subjects aged between eight and 18 years, randomly selected from public and private schools in Natal, Northeast Brazil. Thirtytwo anthropometric variables were measured following the recommendations of the International Society for the Advancement of Kineanthropometry (ISAK). The assessment of sexual maturation was based on the observation of two experienced experts, who identified the pubertal development according to Tanner guidelines (1962). Results: The anthropometric variables showed a significant increase of their values during the advancement of pubertal development (p<0.05). The following variables showed the best value for prediction of maturational groups: sitting height, femoral biepicondylar diameter, forearm girth, triceps skinfold, tibiale laterale and acromiale-radiale bonelenghts. These variables were able to estimate the pubertal stages in 76.3% of the sujects. Conclusion: The anthropometric characteristics showed significant differences between the moments of maturational stages, being found, representatively, seven variables that best predict the stages of sexual maturation...

Discriminant analysis of pubertal maturation in young males based on anthropometric characteristics / Analise discriminante da maturacao puberal de jovens do sexo masculino, a partir das caracteristicas antropometricas

The relationship between anthropometric variables and maturation stages is important for a more detailed monitoring of pubertal development and may provide a suitable tool for clinical diagnosis. The aim of this study was to analyze the predictive contribution of anthropometric variables to pubertal maturation using multivariate discriminant analysis. A total of 190 boys aged 8 to 18 years, from public and private schools in Natal, Brazil, participated in the study. Thirty-two anthropometric variables were measured and pubertal maturation was evaluated objectively by observing pubic hair development. Measures of central tendency and dispersion, inferential analysis of variance, and multivariate discriminant analysis were used for statistical analysis. Pubertal advancement was accompanied by significant changes in anthropometric variables (p<0.05). Discriminant analysis identified eight variables with a high predictive capacity of pubertal maturation: age, sitting height, biacromial breadth, acromiale-radiale, trochanterion-tibiale laterale and tibiale laterale bone lengths, and abdominal and forearm girths. The anthropometric variables showed a high correlation with the classification of pubertal maturation, demonstrating a high predictive level among them. These findings indicate the possibility of developing a predictive equation for pubertal stages.

A relação entre a antropometria e os momentos maturacionais é de grande importância para o acompanhamento mais detalhado do desenvolvimento puberal, pois pode ser considerado como um meio externo adequado para o diagnóstico clínico. O objetivo do presente estudo foi analisar a contribuição preditiva das variáveis antropométricas sobre a maturação puberal, a partir do método multivariado de análise discriminante. Foram avaliados 190 sujeitos do sexo masculino, entre oito e 18 anos, alunos de escolas públicas e privadas de Natal, Brasil. Trinta e duas variáveis antropométricas foram mensuradas e a avaliação da maturação puberal foi realizada a partir do método objetivo da pilosidade púbica. A estatística foi representada pelos valores de tendência central e seus derivados, e de forma inferencial, pela Análise de Variância e análise discriminante multivariada. O avanço dos estágios puberais foi acompanhado de modificações significativas das variáveis antropométricas (p< 0,05). A análise discriminante identificou oito variáveis com alta capacidade preditiva da maturação puberal, sendo elas a idade, ATC, diâmetro bi-acromial, comprimentos ósseos acrômio-radial, trocânter-tibial e tibial, e perimetrias de abdômen e antebraço. Estas variáveis foram responsáveis por estimar os estágios puberais com índice preditivo de 77,4% de chance de acerto, confirmando a alta relação entre estes parâmetros. As variáveis antropométricas apresentaram uma alta relação com a classificação da maturação puberal, demonstrando um alto nível preditivo entre elas, e confirmando a viabilidade da criação de uma equação preditiva dos estágios puberais.